/*
 *
 *  * Copyright 2015 Skymind,Inc.
 *  *
 *  *    Licensed under the Apache License, Version 2.0 (the "License");
 *  *    you may not use this file except in compliance with the License.
 *  *    You may obtain a copy of the License at
 *  *
 *  *        http://www.apache.org/licenses/LICENSE-2.0
 *  *
 *  *    Unless required by applicable law or agreed to in writing, software
 *  *    distributed under the License is distributed on an "AS IS" BASIS,
 *  *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  *    See the License for the specific language governing permissions and
 *  *    limitations under the License.
 *
 */

package org.deeplearning4j.datasets.iterator;

import lombok.Getter;
import org.deeplearning4j.datasets.fetchers.BaseDataFetcher;
import org.nd4j.linalg.dataset.DataSet;
import org.nd4j.linalg.dataset.api.DataSetPreProcessor;
import org.nd4j.linalg.dataset.api.iterator.DataSetIterator;

import java.util.List;

/**
 * Baseline implementation includes
 * control over the data fetcher and some basic
 * getters for metadata
 * @author Adam Gibson
 *
 */
public class BaseDatasetIterator implements DataSetIterator {

	protected int batch,numExamples;
	protected BaseDataFetcher fetcher;
	@Getter	protected DataSetPreProcessor preProcessor;
	
	
	public BaseDatasetIterator(int batch, int numExamples, BaseDataFetcher fetcher) {
		this.batch = batch;
		if(numExamples < 0)
			numExamples = fetcher.totalExamples();
		
		this.numExamples = numExamples;
		this.fetcher = fetcher;
	}

	@Override
	public boolean hasNext() {
		return fetcher.hasMore() && fetcher.cursor() < numExamples;
	}

	@Override
	public DataSet next() {
		fetcher.fetch(batch);
		DataSet result = fetcher.next();
		if(preProcessor != null) {
			preProcessor.preProcess(result);
		}
		return result;
	}

	@Override
	public DataSet next(int num) {
		fetcher.fetch(num);
		DataSet next =  fetcher.next();
		if(preProcessor != null)
			preProcessor.preProcess(next);
		return next;
	}

	@Override
	public void remove() {
		throw new UnsupportedOperationException();
	}

	@Override
	public int totalExamples() {
		return fetcher.totalExamples();
	}

	@Override
	public int inputColumns() {
		return fetcher.inputColumns();
	}

	@Override
	public int totalOutcomes() {
		return fetcher.totalOutcomes();
	}

	@Override
	public boolean resetSupported(){
		return true;
	}

	@Override
	public boolean asyncSupported() {
		return true;
	}

	@Override
	public void reset() {
		fetcher.reset();
	}

	@Override
	public int batch() {
		return batch;
	}

	@Override
	public int cursor() {
		return fetcher.cursor();
	}

	@Override
	public int numExamples() {
		return numExamples;
	}

    @Override
    public void setPreProcessor(DataSetPreProcessor preProcessor) {
        this.preProcessor = (DataSetPreProcessor) preProcessor;
    }

	@Override
	public List<String> getLabels() {
		return null;
	}


}
